WILLIAMSWARN BrewMaster, Руководство пользователя

Страница: 54 / 80

54
BACKGROUND
For the average 5% alcohol beverage, the yeast produces during
fermentation about 10 times the carbon dioxide we need in the
final beer. So we only need to keep about 10% (and let the rest
escape) and the beverage is fully carbonated.
The WilliamsWarn is designed to be able to retain the required
amount of carbon dioxide for a range of beverages. We control
the amount of retained carbon dioxide by controlling the
pressure during fermentation and this we do by setting the VPRV
(Variable Pressure Relief Valve) at a certain pressure relief point.
The pressure builds during the first day of fermentation for
ales and 2
nd
day for lagers and then automatically releases
to emit the excess carbon dioxide we don’t need. But by then
the beverage is fully carbonated and that is the advantage
of the WilliamsWarn – there is no need to keg or bottle flat
beer and then go through a specialised carbonation step after
fermentation is over.
CARBONATION LEVELS FOR BEVERAGE STYLES
Carbonation is a function of temperature and pressure. So when
we chose a brew to make, we need to first choose the carbonation
level we want and the dispense temperature we want and then
we can calculate the correct pressure we need to dispense at.
This knowledge then tells us what pressure to ferment at and
control to on the first few days with the VPRV.
Different beverages traditionally have different final carbonation
levels. These can be seen in the Table 1 below.
These are guidelines only and you may prefer to produce
a highly carbonated English Ale if that is your personal
preference. However in beer competitions, being closer to
what is traditional may be important with regards to the
scoring system beer tasting judges may use.
Different beverages traditionally have different final tem-
peratures they are consumed at. Some approximate guidelines
can be seen in Table 2 below.
These are also guidelines and you as the brewer may choose to
dispense at a temperature not within these ranges, if that is your
personal preference.
SETTING YOUR CARBONATION LEVEL
Carbonation is a function of temperature and pressure. You can
control the amount of carbonation you want in the final beverage
by the following steps.
Step 1: Decide what level of CO
2
you want as read from Table 1.
Step 2: Decide what temperature you want to drink the beverage
at as shown in Table 2.
Step 3: Use Chart 1 to determine what final dispense pressure
you need on your gas cylinder (the y-axis on the graph) in order
to achieve this level of carbonation. Start on the x-axis at the
carbonation level you want, take a vertical line up to the line
on the graph for your chosen temperature. The lines on the
chart read off a range from 1°C to 13°C (34-55°F). Then take
a horizontal line left to the vessel pressure you will need when
dispensing the beverage.
Step 4: Set you gas cylinder regulator at this pressure setting.
APPENDIX FIVE:
THE VPRV AND
CARBONATION
BEVERAGE TYPICAL GRAMS PER LITRE CO
2
British Ales 3.0 - 4.0
Porter, Stout 3.5 - 4.5
Belgian Ales 4.0 - 4.5
American Ales 4.5 - 5.5
European Lagers, Belgian Lambics 5.0 - 5.5
Some Lagers, New World Ales 5.5 - 6.0
Cider and Mead Still - 8.0
American Wheat 5.5 - 6.5
German Wheat Beers 6.5 - 8.0
BEVERAGE TYPICAL SERVING TEMPERATURE
Lagers 1 - 7°C / 34 - 45°F
Ales in New World Countries 1 - 8°C / 34 - 46°F
Wheat Beers 6 - 10°C / 43 - 50°F
British and Belgian Ales 7 - 13°C / 45 -55°F
Cider and Mead 5 - 16°C / 41 - 61°F
Strong Dark Ales and Barley Wines 10 - 15°C / 41 - 61°F
TABLE 1
TABLE 2